Social Like buttons

On top of my posts I have social like buttons. I’m trying to figure out how to control them. Are they a plugin? I’ve checked my plugins list and none of them are connected to these buttons. Are they standard with wordpress? Or the theme? How can I turn them on or off? There is only 4: facebook, twitter, google+ and stumbleupon. I’d like to add email and print to them too. If I install a plugin with other like buttons, it just adds it too my post and then I have too many on the page. How can I fix this? And also, how can you tell who is liking your site or forcing someone to login to be able to like. So many questions i know, any help would be appreciated!
Here’s a link to one of the posts so you can see what I mean:

Thanks guys!